Specimen holder assembly



June 3, 1947. J.-HXLLIER 2,421,696

v SPECIMEN HOLDER ASSEMBLY Filed March 1. 1945 1 IN V EN TOR. JAMES 11/41/5 arrows 5y Patented June 3, 1947 2,421,696 SPECIMEN HOLDER ASSEMBLY James Hillier, Cranbury, N. J assignor to Radio Corporation of America, a corporation of Delaware Application March 1, 1945', Serial No. 580,406

7 Claims.

The present invention relates to electron microscopes and more particularly to an improvement in specimen holders.

Some of the objects of the present invention are to provide an improved specimen holder; to provide a novel stage and specimen holder assembly;

to provide a mounting for a specimen holder wherein provision is made for tilting thespecimen holder to obtain stereoscopic effects; to provide a readily demountable specimen holder; to provide a specimen chamber, specimen holder, and stage assembly wherein theholder is readily accessible for changing specimens or adjusting to a selected position with reference to the axis of the column; to provide means whereby a specimen holder can be swung about its longitudinal axis through a scope showing a specimen holder and stage assembly embodying one form of the presentinvention;

Figure 2 represents a front elevation of the specimen holder;

Figure 3 represents a side elevation of the specimen holder; V

Figure 4 represents an end elevation of the specimen holder Viewed from the right of Fig. 3;

Figure 5 represents a section on line 55 of Fig. 2; and a Figure 6 represents a sectional detail on an enlarged scale of the end of the specimen holder in the specimen holder of Fig. 1.

Referring to the drawings, one form of. the specimen holder of the invention comprises two elongated members I0 and II, the former having a convex arcuate groove |2 extending lengthwise at the rear thereof, and the latter having a c0ncave arcuate face l3 extending lengthwiseat the front thereof, said groove 2 and face l3being complementally arcuate whereby the member which carries the clip M for mounting the specimen unit can be turned about its longitudinal axis and move freely relative to the member I I. The two members It and I l are held in contact by a biasing spring l5 stretched between a pin l6 and a fixed lug The front face of the member I0 is notched transversely to seat the pin l6 and apertures l8 and 2|] are provided in the respective members l0 and II for conveniently bringing the spring If: to its attaching position with the lug H. The lug H is formed as a part of a base 2| which serves as a mount for the member II, and is attached thereto by screws 22. A friction spring 23 is also held by the screws 22 and hes along the outer face of the base 2| in order to react against the juxtaposed face of the stage 24.

For removably mounting the specimen holder on the stage 24, the base 2| is so dimensioned as to project at each side of the member I in order to fit within and havesliding relation within a way formed by two parallel undercut rails 25, preferably formed integral with the stage 24. The depth of the way is such as to receive the thickness of the base 2| plus the friction spring 23 when under compression. Thus, when the specimen holder is guided into operative position, the spring pressure acts as a rigid holding means: to prevent holder displacement when the specimen is under observation. When thus fixed in position, the through hole 26, which directs the electron'be'am upon the specimen, is located coaxially with respect to the column of the microscopeand to the hole I9 in the stage 24. It should benoted that the axis of rotation of the specimen holder is at right angles to the axis of the column as well as to the electron beam, an important 'feature inthat it not only properly locates the object or specimen plane transversely of the beam but brings the holder to a readily accessible position. For maintaining the portions of the through hole 26, which are respectively in the member III, the member H, and the base 2|, in alinement, a pin 21 is fixed to the base 2| and to themember H in order to project and ride within a slot 28, transversely cut in the rear face of the member I0. Thus, the member It can beangularly turned without disturbing the alined through hole relation of the parts. Furthermore, it should be noted that the base 2| projects at its lowerend in order to seat upon shoulders 30 formed as a part of the stage 24 to thereby serve as a means which ensures the accurate coaxial alinement of the specimen holder hole and the axis of the column so that the electron. beam passes through the center of the plane of the specimen.

As a means to indicate the angular relationbetween the members It and H, a pointer 3| projects laterally from the member l0 beyond the upper end of both the member and base 2| and is in a location for ready observation when the closure 32 over the access opening 33 leading to the specimen chamber 34 of the microscope is removed. Stops 35 straddle the pointer 3| in spaced relation to form limits of angular movement and are here shown as part of the lug ll.

In Fig. l the lens unit 36 and electron gun unit 31 are fragmentarily indicated to illustrate the general assembly with which the specimen holder of the invention is associated.

For normal or symmetrical viewing of the specimen, the pointer 3| is located in mid-position, but for stereoscopic viewing the pointer 31 is turned through the desired angle in either direction and thus the specimen can be viewed or photographed at a selected angle to One side in close proximity to the access opening 33 it' can be quickly reached by removing the closure 3-2 which is normally sealed under atmospheric pressure. It should also be noted thatthe' specimenholder is mounted radially of, the stage.

so thatv the sliding connection allows the holder to be readily withdrawn for specimen replacement. This construction obviates the difficulty attendant to the replacement of specimen holdem which are disposed coaxial'ly of the electron beam.

I claim as my invention:

1. A specimen holder for electron microscopes consisting of an elongated member arranged to be fixed and having an arcuate groove extending lengthwise thereof, a second member having an arcuate groove complemental to the arcuate face of said fixed member and arranged to turn about the axis of said groove, means for mounting a specimen on said movable member with the plane of the specimen coincident with said axis,- and means permitting turning of said movable member relative to said fixed member while maintaining said arcuate groove and face in contact.

2. A specimen holder for electron microscopes consisting of an elongated member arranged to be fixed and having an arcuate groove extending lengthwise thereof, a second member having an arcuate face complemental to the arcuate groove of said fixed member and arranged to turn about the axis of said groove, means for mounting a specimen on said movable member with the plane of the specimen coincident with said axis, and biasing means holding said arcuate groove and face together.

' 3'. A specimen holder for electron microscopes consisting of an elongated member arranged to be fixed' and having an arcuate groove extending lengthwise thereof, a second member having an arcuate face complemental to the arcuate groove of said fixed member and arranged to turn about the axis of said groove, means for mounting a specimen on said movable member with the plane of the specimen coincident with said axis, means permitting turning of said movable member relative to said fixed member while maintaining said to limit the turning movement of said movable member.

4. In an electron microscope of the type having a column with its axis alined with the beam of an electron gun, the combination of a stage having an opening coaxial with said axis, and a specimen holder mounted to slide radially of said stage and normally positioning specimen in register with said stage opening, said holder including two arcuate contacting faces for angularly varying the plane of said specimen with respect to said electron beam.

5:. In an electron microscope of the type having acolumn with its axis alined with the beam of an electron gun, the combination of a stage having an opening coaxial with said axis, a specimen holder includin a member arranged to turn about. an axis perpendicular to said electron beam in assembled position, means for mounting a specimen on said member with its plane coincident with said member axis, said holder locating said specimen in register with said stage opening, and means for removably mounting said holder in juxtaposed relation to said stage.

6; In an electron microscope of the type: having a column with its axis alined with the beam of an electron gun, the combination of a. casing forming a specimen chamber, a specimen holder including a member arranged to turn relatively, means for removablymounting said hold-- er in said casing with the turning axis of said member perpendicular to said electron beam, and means for mounting a specimen on said turnable member with its plane coincident with-member axis.

7. In an electron microscope of the type having a column with its axis coaxial with the beam of an electron gun, the combination of a casing forming a specimen chamber, a stage in said chamber having an opening alined with said axis and a pair ofundercut ribs forming a way radially of said stage, a base arranged to slide in said Way, a member fixed to said base having an arcuate groove extending longitudinally thereof, a second member having an arcuate face complemental to said fixed member groove; means maintaining said groove and face in contact but permitting said second member to turn about an axis parallel to said stage way, and means mounting a specimen on said movable member in a plane perpendicular to and intercepting said electron beam but coincident, with saidmember I REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,272,353 Ruska Feb. 10, 1942 2,360,677 Hillier Oct, 17, 1944 2,220,973 Marton Nov. 12,1940 2,253,542 Von Ardenne Aug. 26,1941 

